1. Field of Invention
The invention relates to a length measuring system with a measurement element in the form of a flexible strip and comprises a measurement body which can be scanned with a measuring unit of the respective length measuring system.
2. Related Art
Strip-like measurement elements which consist of plastic and have a multiplicity of magnetisable particles which are embedded in the plastic are known from the prior art. These elongate measurement elements are generally provided with a measurement body which can for example comprise a length code or a sequence of equidistant position markings. The measurement body is generally produced by magnetising individual regions of the respective measurement element. To detect the respective length measurement data or position information, a measuring unit with a reading head is for example used for scanning the measurement body, the respective reading head generally proceeding by contactless scanning at a relative distance from the measurement element. The measurement element can generally be fixed by means of an adhesive connection to a support structure which holds the measurement element in a predefined spatial arrangement. Attachment by means of an adhesive connection is however disadvantageous in that permanent secure positioning of the measurement element on the support structure cannot be guaranteed. Although measurement elements consisting of plastic are protected from wear by the contactless scanning, the necessary minimum distance between the measurement element and the reading head means that the accuracy of the respective length measurement or determination of position is limited, especially as the magnetised regions of the measurement element which contain length information or position information must generally have a minimum size so that they can be reliably scanned by the respective reading head from a predefined distance.
Furthermore, optical systems or strips are known from the prior art in which the measurement strip is scanned optically by a scanning unit in order to acquire length measurement data contactlessly. The disadvantage of these measurement strips is however that the measurement strip can become very dirty, as a result of which error-free scanning by the optical scanning unit can no longer be reliably ensured.